Question

PLEASE HELP!!

Answer 1

We need two definitions. 
Two shapes are congruent if you can turn one into another using translation, rotation, and reflection.
Two shapes are similar if you rescale one them into a shape that is congruent to the other.
We can conclude from this that in euclidian geometry all circles are similar.
We can shrink the first circle to get the second one.
Scale factor would be 1/3 as circle 1 has the radius that is 3 times the radius of circle 2.